Box plots

In descriptive statistics, a box plot or boxplot is a convenient way of graphically depicting groups of numerical data through their quartiles. Box plots may also have lines extending vertically from the boxes (whiskers) indicating variability outside the upper and lower quartiles, hence the terms box-and-whisker plot and box-and-whisker diagram.

Carly Capitula at Interworks wrote this great post, which goes into some detail about the chart type itself, before showing how to create one in Tableau. This is especially handy as it isn’t the most immediately understood chart type: